Wh to mAh Calculator
Wh to mAh Conversion Calculator – Convert Energy to Battery Capacity
A Wh to mAh Conversion Calculator is a valuable tool for anyone working with batteries, portable devices, or renewable energy systems. It allows you to convert watt-hours (Wh), a measure of energy, into milliampere-hours (mAh), a common measure of battery capacity.
This conversion is essential when comparing batteries, planning battery-powered projects, or estimating how long a device will run.
Understanding Wh and mAh
What Are Watt-Hours (Wh)?
Watt-hours measure energy. They tell you how much total power a battery or device can provide over time.
1 Wh = 1 W × 1 hour
$$
- Example: A 50 Wh battery can supply 50 watts for 1 hour, or 25 watts for 2 hours.
What Are Milliampere-Hours (mAh)?
mAh measures electric charge capacity, indicating how much current a battery can supply over time.
- Example: A 2000 mAh battery can supply 2000 milliamps for 1 hour, or 1000 milliamps for 2 hours.
mAh is commonly used for:
- Smartphones
- Laptops
- Tablets
- Power banks
Wh to mAh Conversion Formula
The formula to convert watt-hours to milliampere-hours depends on battery voltage (V):
mAh = \frac{Wh × 1000}{V}
$$
Where:
- Wh = energy in watt-hours
- V = voltage of the battery
- 1000 converts ampere-hours (Ah) to milliampere-hours (mAh)
Step-by-Step Examples
Example 1: 10 Wh Battery at 5V
mAh = \frac{10 × 1000}{5} = 2000 mAh
$$
Result: 2000 mAh
Example 2: 50 Wh Battery at 12V
mAh = \frac{50 × 1000}{12} ≈ 4166.7 mAh
$$
Example 3: 100 Wh Battery at 3.7V
mAh = \frac{100 × 1000}{3.7} ≈ 27,027 mAh
$$
How the Wh to mAh Calculator Works
- Enter battery energy in watt-hours (Wh)
- Enter battery voltage (V)
- Click Calculate
- Get battery capacity in mAh instantly
Some calculators also allow:
- Reverse calculation: mAh to Wh
- Batch calculations for multiple batteries
- Integration with solar or portable power setups
Practical Applications
- Battery Selection: Match your device requirements with available batteries
- Portable Device Planning: Estimate runtime based on energy usage
- Solar Projects: Determine battery capacity needed to store energy
- Electronics Design: Calculate battery sizing for custom circuits
Quick Reference Table
| Energy (Wh) | Voltage (V) | Capacity (mAh) |
|---|---|---|
| 10 Wh | 5 V | 2000 mAh |
| 20 Wh | 3.7 V | 5405 mAh |
| 50 Wh | 12 V | 4167 mAh |
| 100 Wh | 3.7 V | 27,027 mAh |
Frequently Asked Questions
Can I convert Wh to mAh without knowing the voltage?
No. Voltage is essential because mAh depends on both energy and battery voltage.
How do I calculate device runtime from Wh or mAh?
\text{Runtime (h)} = \frac{\text{Battery capacity (Wh)}}{\text{Device power (W)}}
$$
or
\text{Runtime (h)} = \frac{\text{Battery capacity (mAh)} × V}{1000 × \text{Device power (W)}}
$$
Is mAh the same as Wh?
No. mAh measures charge capacity, Wh measures energy. Voltage connects the two.
Final Thoughts
A Wh to mAh Conversion Calculator is a simple yet powerful tool for:
- Comparing batteries
- Planning portable power systems
- Estimating device runtime
- Designing electronic circuits
By converting Wh to mAh, you can choose the right battery for your device and avoid over- or under-sizing your energy storage solution.
This calculator pairs perfectly with:
- mAh to Wh Converter
- Battery Runtime Calculator
- Solar Battery Sizing Calculator
- Energy Consumption Calculator
Understanding this conversion ensures your devices and projects are efficient, reliable, and well-powered.